4 15s 4th Order Bandpass in a TRUNK?

Okay, so I am working on a box for a Ford Crown Victoria. It can take up unlimited space but is confined to the trunk area. Subs are four Old School Kicker Solobaric S15-4s. These subs were designed around the theory that a subwoofer with twice the moving mass, motor force, etc will behave as an isobaric pair of woofers. This means that they are pretty inefficient, but play deeply in ridiculously small sealed boxes (Kicker calls for 1.5 cf per for these woofers). They are not reccomended for ported enclosures due to the heavy cone and relatively loose suspension.

Since the current subs require sealed boxes, I would like to run them in a 4th order bandpass box. I estimate approximately 17.5 cf gross available for the total enclosure, so figure 14.5 after sub, brace, and port displacement. My impulse is to use one 6 cf sealed enclosure in the back firing into a larger ported side vented through the rear seat area.

What do you guys think? Should I go smaller on the sealed side or keep it at 6? Port is 304 square inches or so.

Amps are to be a matching pair of Old School Hifonics Gen vii Zeus and a single Gemini for now.

Re: 4 15s 4th Order Bandpass in a TRUNK?

Those subs sound incredible in 4th order. One of the best sub setups I ever heard was 4 round solobaric 12's in bandpass in a deville. It was clean and dropped low. I still keep my round 15" solobaric around. I wish kicker just improved on that design instead of going to the square stuff. Those mark the year that solos could sound good and everything after that went to pot IMO.